The present invention relates to novel mercapto quinoline N-oxides, metal complexes thereof and the utilization of the latter in anti-dandruff shampoo compositions and in methods for combatting dandruff.
The precise cause of dandruff in the scalp area is at present unknown. It has been theorized that the skin particles normally shed from the scalp surfaces during the process of aging accumulate and combine with the oils exuded by the scalp to form a condition which enhances the growth of those bacteria, fungi, or other biological agents responsible for the propagation and accumulation of dandruff.
It is emphasized, however, that the above mechanism is at best an unproven theory. One of the major obstacles to a complete acceptance of this theory is the fact that many extremely powerful bactericides and fungicides have no effect whatsoever on the spread of dandruff in the human scalp. Moreover, substances such as elemental sulfur which are not recognized as having potent bactericidal and fungicidal activity are extremely effective in the control of dandruff. Obviously, then, factors other than bacteria and fungi contribute to the growth and spread of dandruff.
Accordingly, the selection of agents suitable for the control of dandruff is necessarily a hit and miss proposition. It is only by the process of trial and error that those skilled in the art have been able to provide the art with effective anti-dandruff agents to date.
One type of such anti-dandruff agent is described in U.S. Pat. No. 3,236,733. The compounds described therein as being useful for combatting dandruff are certain metal salts or complexes of 1-hydroxy-2-pyridinothione. Although providing a high degree of anti-dandruff activity, the metal salts of 1-hydroxy-2-pyridinethiones suffer from the disadvantage that they are slightly toxic, particularly when applied to the scalps of those individuals having unusually sensitive skin. Such individuals experience irritation and reddening of the skin and in certain cases, highly aggravated reactions in the form of open sores, etc., upon application of these thione salts to their scalps.
There exists in the prior art, therefore, the need for an anti-dandruff agent which is highly effective in combatting dandruff and, simultaneously, non-toxic to the scalp or skin.
Accordingly, it is an object of the present invention to provide novel chemical compounds having a high degree of anti-dandruff activity which are non-toxic to the skin or scalp.
It is further object of the present invention to provide an anti-dandruff shampoo composition which is non-toxic to the scalp or skin.
It is still a further object of the present invention to provide a method for combatting dandruff with a composition which is non-toxic to the scalp or skin.